Deadlock in Linux kernel - CVE-2026-45895
Published: May 28, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a livelock condition in quotactl_block() when waiting for a frozen filesystem to thaw. A local user can repeatedly toggle quota operations during filesystem freeze activity to cause a denial of service.
The issue is reliably triggered on non-preemptible kernels when the freezer and quota operations run on the same CPU.
Affected software
Ubuntu
openEuler
python3-perf-debuginfo
python3-perf
perf-debuginfo
perf
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
kernel-headers
kernel-devel
kernel-debugsource
kernel-debuginfo
bpftool-debuginfo
bpftool
kernel
kernel-extra-modules
linux (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi-realtime (Ubuntu package)
How to mitigate CVE-2026-45895
python3-perf-debuginfo - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
python3-perf - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
perf-debuginfo - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
perf - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-tools-devel - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-tools-debuginfo - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-tools - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-source - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-headers - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-devel - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-debugsource - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-debuginfo - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
bpftool-debuginfo - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
bpftool - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel - addressed in versions 6.6.0-145.1.15.153, 6.6.0-145.3.15.146
kernel-extra-modules - update to 6.6.0-145.3.15.146
linux (Ubuntu package) - addressed in versions 6.8.0-134.134, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61+fips1, 6.8.0-1058.61~22.04.1, 6.8.0-1060.61, 6.8.0-1060.63+fips1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69, 6.8.0-1063.69+fips1, 6.8.1-1055.56, 6.8.1-1055.56~22.04.1
linux-azure-fips (Ubuntu package) - addressed in versions 6.8.0-134.134+fips1, 6.8.0-1062.69+fips1
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1029.30
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1045.48, 6.8.0-1057.58~22.04.1, 6.8.0-1058.61.1, 6.8.0-1058.64, 6.8.0-1060.61~22.04.1, 6.8.0-1060.63~22.04.1, 6.8.0-1063.69~22.04.1
linux-raspi (Ubuntu package) - update to 6.8.0-1060.64
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-raspi-realtime (Ubuntu package) - update to 6.8.0-2049.50
External References
- https://git.kernel.org/stable/c/02bb1500f1479750e6557c8044f6a2d7e9d30c12
- https://git.kernel.org/stable/c/37ccd48cf35f3c8b9f2ea961a7b486b91eb71a82
- https://git.kernel.org/stable/c/414259caf81a397563fc9baca9c0ef856c4a97cf
- https://git.kernel.org/stable/c/53b2314b26b6640a3657cc924de63a1a8f26ac4d
- https://git.kernel.org/stable/c/77449e453dfc006ad738dec55374c4cbc056fd39
Related Security Bulletins
- Deadlock in Linux kernel quota
- openEuler 24.03 LTS SP3 update for kernel
- openEuler 24.03 LTS SP1 update for kernel
- Ubuntu update for linux
- Ubuntu update for linux-nvidia-tegra
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-raspi-realtime
- Ubuntu update for linux-raspi
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-hwe-6.8